(a) Field of the Invention
This invention relates to a novel process for the purification of the water-soluble yellow dye which chemically is a mixture in the form of the sodium salts of the products produced by the sulfonation of 2-(2-quinolinyl)-1,3-indandione. Said yellow dye, which is variously known as D and C Yellow 10, Quinoline Yellow WS or Quinoline Yellow, is used as a color additive in drugs and cosmetics. This invention also relates to certain novel organic amine salts of the mixture of sulfonation products obtained from the sulfonation of 2-(2-quinolinyl)-1,3-indandione and their use in the novel process of this invention.
(b) Description of the Prior Art
The prior art appears to be devoid of teachings of organic amine salts of the mixture of sulfonation products obtained from the sulfonation of 2-(2-quinolinyl)-1,3-indandione and/or the use of such salts in a process for the purification of Quinoline Yellow WS. The following items, to date, appear to constitute the most relevant prior art with regard to the instant invention.
Kirk-Othmer "Emcyclopedia of Chemical Technology," Third Edition (1979), John Wiley & Sons, Volume 6, page 577 describes D&C Yellow No. 10 (also known as Quinoline Yellow and Quinoline Yellow WS) as the mixed mono- and disodium salts of the 6-mono- and 6,5'-disulfonic acids of 2-(2-quinolinyl)-1,3-indandione having the Colour Index designation of C.I. Acid Yellow 3 and C.I. No. 47005.
Colour Index (3rd Edition, 1971), The Society of Dyers and Colourists, Volume 4, page 4435 discloses the aluminum salt of C.I. Acid Yellow 3 and assigns the designation Pigment Yellow 115 and C.I. No. 47005:1 to the product.
U.S. Pat. No. 290,585, which issued Dec. 18, 1883 teaches the preparation of Quinoline Yellow by the condensation of "chinaldine" with phthalic anhydride in the presence of a catalytic amount of zinc chloride at 190.degree. to 210.degree. C. and the subsequent sulfonation of the resultant 2-(2-quinolinyl)-1,3-indandione with isolation of the sulfonated product in either the sodium salt or calcium salt form "to render it soluble in water--."
In "The Chemistry of Synthetic Dyes," Vol. VIII, edited by K. Venkataraman, Academic Press (1978), at page 107, it is stated that most commercial Solvent Blue 38 dyes, which are amine salts of sulfonated copper phthalocyanine, are "probably the diarylguanidine salts."
(c) Patent Activities of Others
U.S. Pat. No. 4,290,812, which issued Sept. 22, 1981 teaches a process for the production of an ink free from foreign salts from a water-soluble technical anionic dye in the form of sulfonic acid sodium salts by dissolving the highly water-soluble dye in water, precipitating the dye from the aqueous solution by addition of an organic amine of the cyclohexyl- or dicyclohexylamine type in the form of an acid salt, converting the precipitated dye into a highly water-soluble form by distillation in the presence of water and a water-soluble amine of the alkanolamine type of low volatility, and finally dissolving the water-soluble dye in a solvent to obtain a dye solution.